JP6916294B2 - Thermal printer - Google Patents

Description

The present invention relates to a thermal printer.

Conventionally, in a thermal printer, a thermal paper is sandwiched between a thermal head and a platen roller to press the thermal paper against the thermal head, and in that state, the thermal paper is heated by a heat generating element provided in the thermal head. As a result, a configuration is adopted in which an image is formed on thermal paper.

In such a thermal printer, the thermal paper can be sandwiched at an appropriate pressure by adjusting the gap between the thermal head and the platen roller to an appropriate interval. As a result, the quality of the image formed on the thermal paper can be improved, and the thermal paper can be appropriately conveyed. Therefore, conventionally, regarding a thermal printer, a technique for adjusting a gap between a thermal head and a platen roller has been disclosed.

For example, in Patent Document 1 below, in a thermal printer, the tip of a screw member provided on a member holding a thermal head is brought into contact with the upper surface of a frame on which a platen roller is arranged, and the screw member is rotated. A technique has been disclosed in which the clearance dimension between the thermal head and the platen roller can be adjusted by adjusting the protrusion amount of the screw member.

JP-A-2009-119733

However, the thermal printer of Patent Document 1 employs a configuration in which a screw member, which is an adjusting means, is brought into contact with the upper surface of the frame. Therefore, in the thermal printer of Patent Document 1, for example, even if the gap dimension is once adjusted to an appropriate dimension, the frame is affected by deformation over a long period of use, and the above is described. There is a risk that the gap dimension deviates from the appropriate dimension, or the contact angle of the thermal head with respect to the surface of the thermal paper deviates from the appropriate angle. In this case, the quality of the image formed on the thermal paper may be deteriorated, or the thermal paper may not be properly conveyed. Therefore, there is a demand for a thermal printer capable of maintaining the gap dimension between the thermal head and the platen roller and the contact angle of the thermal head with respect to the surface of the thermal paper with high accuracy.

The thermal printer of one embodiment includes a frame, a platen roller rotatably supported on the frame via a bearing, a thermal head provided facing the platen roller, and the thermal head with respect to the frame. Intervening between the support member that rotatably supports the platen roller, the rotation shaft of the platen roller, and the thermal head, and in contact with at least one of the component member of the platen roller and the component member of the thermal head. The platen roller is provided with an adjusting mechanism for adjusting the gap between the thermal head and the platen roller by adjusting the distance between the rotation shaft of the platen roller and the thermal head.

According to one embodiment, it is possible to provide a thermal printer capable of maintaining the gap dimension between the thermal head and the platen roller and the contact angle of the thermal head with respect to the surface of the thermal paper with high accuracy. can.

It is a perspective view which shows the appearance of the thermal printer which concerns on one Embodiment. It is a top view of the thermal printer which concerns on one Embodiment. It is a side view of the thermal printer which concerns on one Embodiment. It is a front view of the thermal printer which concerns on one Embodiment. FIG. 5 is a cross-sectional view taken along the line AA of the thermal printer shown in FIG. It is a side view which shows the 1st Embodiment of the adjustment mechanism provided in the thermal printer which concerns on one Embodiment. It is a front view which shows the 1st Embodiment of the adjustment mechanism provided in the thermal printer which concerns on one Embodiment. It is a partially enlarged view which shows the 1st Embodiment of the adjustment mechanism provided in the thermal printer which concerns on one Embodiment. It is a side view which shows the 2nd Embodiment of the adjustment mechanism provided in the thermal printer which concerns on one Embodiment. It is a front view which shows the 2nd Embodiment of the adjustment mechanism provided in the thermal printer which concerns on one Embodiment. It is a partially enlarged view which shows the 2nd Embodiment of the adjustment mechanism provided in the thermal printer which concerns on one Embodiment. It is a side view which shows the 3rd Embodiment of the adjustment mechanism provided in the thermal printer which concerns on one Embodiment. It is a front view which shows the 3rd Embodiment of the adjustment mechanism provided in the thermal printer which concerns on one Embodiment. It is a partially enlarged view which shows the 3rd Embodiment of the adjustment mechanism provided in the thermal printer which concerns on one Embodiment.

Hereinafter, one embodiment will be described with reference to the drawings.

(Basic configuration of thermal printer 100)
First, the basic configuration of the thermal printer 100 according to the embodiment will be described with reference to FIGS. 1 to 5.

FIG. 1 is a perspective view showing the appearance of the thermal printer 100 according to the embodiment. FIG. 2 is a plan view of the thermal printer 100 according to the embodiment. FIG. 3 is a side view of the thermal printer 100 according to the embodiment. FIG. 4 is a front view of the thermal printer 100 according to the embodiment. FIG. 5 is a cross-sectional view taken along the line AA of the thermal printer 100 shown in FIG. In the following description, for convenience, the Z-axis direction in the figure is the vertical direction or the vertical direction, the X-axis direction in the figure (the transport direction of the heat-sensitive paper P) is the front-rear direction, and the Y-axis direction in the figure (heat-sensitive paper). The direction (direction orthogonal to the transport direction of P) is the lateral direction or the left-right direction.

The thermal printer 100 shown in FIGS. 1 to 5 presses the thermal paper P against the thermal head 105, and in that state, heats the thermal paper P with a heat generating element provided on the thermal head 105 to form the thermal paper P. It is a so-called thermal printer that can form images.

As shown in FIGS. 1 to 5, the thermal printer 100 includes a frame 101, a platen roller 102, a support member 103, a plate 104, a thermal head 105, an FPC (Flexible Printed Circuits) 106, and a paper feed guide 107. It is configured to include a paper feed roller 108 and a pressure welding spring 109.

The frame 101 is a saucer-shaped member formed by processing a metal plate and forming a substantially thin rectangular parallelepiped. The frame 101 has a bottom surface portion having a rectangular shape when viewed in a plan view from above, and a side wall portion vertically erected along both left and right edge portions of the bottom surface portion.

The platen roller 102 is a columnar member that extends in the lateral width direction (Y-axis direction in the drawing) between the left and right side wall portions of the frame 101. Both ends of the rotating shaft 102A of the platen roller 102 are pivotally supported by bearings (not shown) attached to the left and right side wall portions of the frame 101. The platen roller 102 is provided so as to face the thermal head 105. The platen roller 102 can press the surface of the thermal paper P against the thermal head 105 by sandwiching the thermal paper P (see FIG. 5) in the gap between the platen roller 102 and the thermal head 105. Further, the platen roller 102 can transport the thermal paper P in a predetermined transport direction (X-axis positive direction in the drawing) by rotating by driving various motors (for example, a stepping motor or the like, which is not shown). For example, the platen roller 102 uses an elastic material such as rubber for its roller portion. Further, for example, in the platen roller 102, a relatively hard material such as metal is used for the rotating shaft 102A. The platen roller 102 is not limited to one that is rotated by driving a motor, and may be one that rotates in response to the transfer of the thermal paper P.

The support member 103 is a member formed by processing a metal plate. The support member 103 supports the thermal head 105 together with the plate 104. The support member 103 is rotatable in the vertical direction (Z-axis direction in the drawing) with respect to the frame 101. Specifically, the support member 103 has two left and right arm portions 103A and 103B and a connecting portion 103C. The two arms 103A and 103B are from the vicinity of the center in the front-rear direction (X-axis direction in the figure) of the frame 101 to the transport direction of the thermal paper P (X in the figure) along the upper edge of the side wall portion of the frame 101. It is a part that extends in the positive direction of the axis). The two arms 103A and 103B are elongated flat plates, and are erected so that their surfaces are substantially vertical and are located on substantially the same plane as the surface of the side wall of the frame 101. ing. The two arms 103A and 103B are connected to each other by a flat plate-shaped connecting portion 103C having a substantially horizontal flat surface at the tip portion thereof. A plate 104 and a thermal head 105 are attached to the bottom surface of the connecting portion 103C. Further, the two arm portions 103A and 103B are axially supported on the side wall portion of the frame 101 at the terminal portions thereof. As a result, the support member 103 supports the plate 104 and the thermal head 105 in the vertical direction (Z-axis direction in the drawing) with respect to the frame 101 with the end portions of the two arm portions 103A and 103B as rotation axes. It is rotatable to.

The plate 104 is attached to the bottom surface of the connecting portion 103C constituting the support member 103. The plate 104 is a flat plate-like member having a substantially horizontal flat surface. For example, the plate 104 is made of a relatively hard material such as metal.

The thermal head 105 is provided on the bottom surface of the plate 104 so as to face the platen roller 102. The thermal head 105 is provided with a plurality of heat generating elements arranged side by side in the horizontal width direction (the Y-axis direction in the drawing, the direction orthogonal to the transport direction of the thermal paper P). A slight gap smaller than the thickness of the thermal paper P is formed between the thermal head 105 and the platen roller 102. For example, when the thickness of the thermal paper P is 0.25 mm, a gap of 0.15 mm is formed between the thermal head 105 and the platen roller 102. As a result, when the thermal paper P is inserted between the thermal head 105 and the platen roller 102, the surface of the thermal paper P can be pressed against the thermal head 105 with an appropriate pressure. With the surface of the thermal paper P pressed against the thermal head 105, the heat generation of the plurality of heat generating elements is controlled by the control signal supplied from the external circuit via the FPC 106, so that the thermal head 105 is pressed against the thermal paper P. The image can be formed.

The FPC 106 is a member that connects the thermal head 105 and an external circuit (not shown) in order to supply a control signal to the thermal head 105. The FPC 106 is a film-like member having a structure in which wiring made of a metal film is sandwiched between resin materials such as polyimide. Since the FPC 106 has flexibility, it can be bent.

The paper feed guide 107 and the paper feed roller 108 are provided at the rear of the frame 101. The thermal paper P is placed on the paper feed guide 107. By rotating, the paper feed roller 108 sends out the thermal paper P placed on the paper feed guide 107 into the gap between the platen roller 102 and the thermal head 105.

One end of the pressure welding spring 109 is hooked on the tip end portion of the support member 103, and the other end is hooked on the frame 101. As a result, the pressure welding spring 109 urges the support member 103 downward toward the frame 101 and keeps the support member 103 in a closed state. When the support member 103 is closed, the clearance dimension between the thermal head 105 and the platen roller 102 is maintained at an appropriate dimension.

In the thermal printer 100 configured in this way, the thermal paper P is fed into the gap between the thermal head 105 and the platen roller 102 by the paper feed guide 107 and the paper feed roller 108. As a result, the thermal head 105 and the platen roller 102 sandwich the thermal paper P that has been sent out. In that state, a control signal corresponding to the print data is input to the thermal head 105 from an external circuit (not shown) via the FPC 106. The thermal head 105 heats the thermal paper P by generating heat from a plurality of heating elements in response to the input control signal. As a result, the thermal head 105 forms an image corresponding to the print data on the thermal paper P.

(Example of adjustment mechanism)
In addition to the basic configurations described with reference to FIGS. 1 to 5, the thermal printer 100 of one embodiment further includes an adjusting mechanism for adjusting the gap between the thermal head 105 and the platen roller 102. For convenience, the adjustment mechanism is not shown in FIGS. 1 to 5. Hereinafter, examples of the adjustment mechanism included in the thermal printer 100 will be specifically described.

(First Example of Adjustment Mechanism)
First, a first embodiment of the adjustment mechanism included in the thermal printer 100 will be described with reference to FIGS. 6 to 8. FIG. 6 is a side view showing a first embodiment of the adjustment mechanism included in the thermal printer 100 according to the embodiment. FIG. 7 is a front view showing a first embodiment of the adjustment mechanism included in the thermal printer 100 according to the embodiment. FIG. 8 is a partially enlarged view showing a first embodiment of the adjustment mechanism included in the thermal printer 100 according to the embodiment.

In the example shown in FIGS. 6 to 8, the thermal printer 100 includes a first adjusting mechanism 110. The first adjusting mechanism 110 has a cam 111 and a fixing screw 112. The cams 111 are rotatably provided at both ends of the rotating shaft 102A of the platen roller 102 with respect to the rotating shaft 102A. Further, the cam 111 is arranged between the columnar roller portion of the platen roller 102 and the bearing 101A attached to the side wall portion of the frame 101. The cam 111 is a disk-shaped member having a certain thickness, and is provided separately from the bearing 101A. A relatively hard material such as resin is used for the cam 111. The center of rotation of the cam 111 is provided at a position away from the center of the cam 111. Therefore, the radius of the cam 111 from the center of rotation differs depending on the position of rotation.

The cam 111 is in contact with the bottom surface of the plate 104 on its upper outer peripheral surface. Therefore, the height position of the plate 104 is adjusted by rotating the cam 111 to change the distance from the center of rotation of the cam 111 (that is, the rotation axis 102A of the platen roller 102) to the bottom surface of the plate 104. Can be done. A thermal head 105 is attached to the bottom surface of the plate 104. Therefore, the height position of the thermal head 105 can be adjusted by rotating the cam 111 to adjust the height position of the plate 104. That is, the gap between the thermal head 105 and the platen roller 102 can be adjusted.

A fixing screw 112 is attached to the outer surface of the cam 111. The fixing screw 112 penetrates the side wall portion of the frame 101. The rotation position of the cam 111 is fixed with respect to the side wall portion of the frame 101 by tightening the fixing screw 112. That is, in the first adjusting mechanism 110 shown in FIGS. 6 to 8, the fixing screw 112 is in a state where the cam 111 is rotated to adjust the gap between the thermal head 105 and the platen roller 102 to an appropriate interval. The state can be maintained by tightening.

As described above, the first adjusting mechanism 110 can directly adjust the gap between the thermal head 105 and the platen roller 102 by the cam 111 interposed between the two. That is, the frame 101 does not intervene in the first adjusting mechanism 110. Therefore, the thermal printer 100 according to the embodiment is provided with the first adjusting mechanism 110, and once the clearance dimension is adjusted to an appropriate dimension, the frame 101 is used even if it is used for a long period of time. The clearance dimension between the thermal head 105 and the platen roller 102 and the contact angle of the thermal head 105 with respect to the surface of the thermal paper P are increased without being affected by the component accuracy, assembly accuracy, clearance, bending, etc. It can be maintained with accuracy.

(Second Example of Adjustment Mechanism)
Next, a second embodiment of the adjustment mechanism included in the thermal printer 100 will be described with reference to FIGS. 9 to 11. FIG. 9 is a side view showing a second embodiment of the adjustment mechanism included in the thermal printer 100 according to the embodiment. FIG. 10 is a front view showing a second embodiment of the adjustment mechanism included in the thermal printer 100 according to the embodiment. FIG. 11 is a partially enlarged view showing a second embodiment of the adjustment mechanism included in the thermal printer 100 according to the embodiment.

In the examples shown in FIGS. 9 to 11, the thermal printer 100 includes a second adjusting mechanism 120. The second adjusting mechanism 120 has a cam lever 121, a fixing screw 122, and a protrusion 123. The cam lever 121 is rotatably provided at both ends of the rotating shaft 102A of the platen roller 102 with respect to the rotating shaft 102A. Further, the cam lever 121 is attached to the side wall portion of the frame 101 and functions as a bearing for the rotating shaft 102A. A relatively hard material such as resin is used for the cam lever 121.

The cam lever 121 has a cam portion 121A and a lever portion 121B at positions protruding outward from the side wall portion of the frame 101. The cam portion 121A is a disk-shaped portion having a certain thickness. The center of rotation of the cam portion 121A is provided at a position away from the center of the cam portion 121A. Therefore, the radius of the cam portion 121A from the center of rotation differs depending on the rotation position.

A protruding portion 123 protruding downward is provided on the tip portion and the lower edge portion of the arm portions 103A and 103B of the support member 103. The cam portion 121A is in contact with the tip end surface of the protrusion 123 on the upper outer peripheral surface thereof. Therefore, the height of the support member 103 is increased by rotating the cam portion 121A to change the distance from the rotation center of the cam portion 121A (that is, the rotation shaft 102A of the platen roller 102) to the tip surface of the protrusion 123. The position can be adjusted. A plate 104 and a thermal head 105 are attached to the support member 103. Therefore, the height position of the thermal head 105 can be adjusted by rotating the cam portion 121A and adjusting the height position of the support member 103. That is, the gap between the thermal head 105 and the platen roller 102 can be adjusted.

A fixing screw 122 is attached to the side wall portion of the frame 101. The fixing screw 122 penetrates the lever portion 121B. The rotation position of the cam lever 121 is fixed with respect to the side wall portion of the frame 101 by tightening the fixing screw 122. That is, the second adjusting mechanism 120 shown in FIGS. 9 to 11 is a fixing screw in a state where the cam portion 121A is rotated to adjust the gap between the thermal head 105 and the platen roller 102 to an appropriate distance. By tightening 122, that state can be maintained.

As described above, the second adjusting mechanism 120 can directly adjust the gap between the thermal head 105 and the platen roller 102 by the cam lever 121 interposed between the two. That is, the frame 101 does not intervene in the second adjusting mechanism 120. Therefore, the thermal printer 100 according to the embodiment is provided with the second adjusting mechanism 120, and once the clearance dimension is adjusted to an appropriate dimension, the frame 101 is used even if it is used for a long period of time. The clearance dimension between the thermal head 105 and the platen roller 102 and the contact angle of the thermal head 105 with respect to the surface of the thermal paper P are increased without being affected by the component accuracy, assembly accuracy, clearance, bending, etc. It can be maintained with accuracy.

(Third Example of Adjustment Mechanism)
Next, a third embodiment of the adjustment mechanism included in the thermal printer 100 will be described with reference to FIGS. 12 to 14. FIG. 12 is a side view showing a third embodiment of the adjustment mechanism included in the thermal printer 100 according to the embodiment. FIG. 13 is a front view showing a third embodiment of the adjustment mechanism included in the thermal printer 100 according to the embodiment. FIG. 14 is a partially enlarged view showing a third embodiment of the adjustment mechanism included in the thermal printer 100 according to the embodiment.

In the example shown in FIGS. 12 to 14, the thermal printer 100 includes a third adjusting mechanism 130. The third adjusting mechanism 130 includes an adjusting screw 131 and a bearing 132. The adjusting screw 131 is provided at both ends of the connecting portion 103C of the support member 103 so as to penetrate the connecting portion 103C from above.

Bearings 132 that pivotally support the rotating shaft 102A of the platen roller 102 are attached to the left and right side wall portions of the frame 101. The bearing 132 has a regulating portion 132A protruding inward of the side wall portion of the frame 101. A relatively hard material such as resin is used for the bearing 132.

The adjusting screw 131 can adjust the amount of protrusion of the support member 103 downward from the bottom surface of the connecting portion 103C by adjusting the screwing amount. The adjusting screw 131 is in contact with the regulating portion 132A of the bearing 132 on its tip surface. Therefore, the height position of the support member 103 is determined by the screwing amount of the adjusting screw 131. Therefore, the height position of the support member 103 can be adjusted by rotating the adjusting screw 131 to adjust the screwing amount of the adjusting screw 131.

A plate 104 and a thermal head 105 are attached to the support member 103. Therefore, the height position of the thermal head 105 can be adjusted by adjusting the screwing amount of the adjusting screw 131 and adjusting the height position of the support member 103. That is, the gap between the thermal head 105 and the platen roller 102 can be adjusted.

The third adjusting mechanism 130 shown in FIGS. 12 to 14 rotates the adjusting screw 131 to adjust the gap between the thermal head 105 and the platen roller 102 to an appropriate distance, and then adjusts thereafter. As long as the screw 131 is not rotated, that state can be maintained.

As described above, the third adjusting mechanism 130 can directly adjust the gap between the thermal head 105 and the platen roller 102 by the adjusting screw 131 interposed between the two. That is, the frame 101 does not intervene in the third adjusting mechanism 130. Therefore, the thermal printer 100 according to the embodiment is provided with the third adjusting mechanism 130, and once the clearance dimension is adjusted to an appropriate dimension, the frame 101 is used even if it is used for a long period of time. The clearance dimension between the thermal head 105 and the platen roller 102 and the contact angle of the thermal head 105 with respect to the surface of the thermal paper P are increased without being affected by the component accuracy, assembly accuracy, clearance, bending, etc. It can be maintained with accuracy.

Although one embodiment of the present invention has been described in detail above, the present invention is not limited to these embodiments, and various modifications or modifications are made within the scope of the gist of the present invention described in the claims. It can be changed.

For example, in the first adjusting mechanism 110, the upper outer peripheral surface of the cam 111 may be deformed so as to come into contact with the thermal head 105 or the support member 103.

Further, for example, in the second adjusting mechanism 120, the upper outer peripheral surface of the cam portion 121A of the cam lever 121 may be deformed so as to be in contact with the thermal head 105 or the plate 104.

Further, for example, in the third adjusting mechanism 130, the tip surface of the adjusting screw 131 may be deformed so as to be brought into contact with the rotating shaft 102A of the platen roller 102.

Further, for example, in the third adjusting mechanism 130, the adjusting screw 131 may be deformed so as to be provided on the thermal head 105 or the plate 104.

The "components of the platen roller" described in the claims include not only the rotation shaft of the platen roller but also the bearing that supports the rotation shaft of the platen roller. That is, the meaning of "contacting the constituent members of the platen roller" described in the claims is not only the case of contacting the rotating shaft of the platen roller but also the case of contacting the bearing that pivotally supports the rotating shaft of the platen roller. It includes.

Further, the "component of the thermal head" described in the claims includes not only the thermal head but also a plate for holding the thermal head and a support member. That is, the meaning of "contacting the constituent members of the thermal head" described in the claims includes not only the case of contacting the thermal head but also the case of contacting the plate and the support member holding the thermal head. Is.

This international application claims priority based on Japanese Patent Application No. 2017-188872 filed on September 28, 2017, and the entire contents of this application are incorporated into this international application.

100 Thermal Printer 101 Frame 102 Platen Roller 103 Support Member 104 Plate 105 Thermal Head 106 FPC
107 Paper feed guide 108 Paper feed roller 109 Pressure welding spring 110 First adjustment mechanism 111 Cam 112 Fixing screw 120 Second adjusting mechanism 121 Cam lever 122 Fixing screw 123 Protrusion 130 Third adjusting mechanism 131 Adjusting screw 132 Bearing

Claims (2)

With the frame
A platen roller rotatably supported by the frame via a bearing,
A thermal head provided facing the platen roller and
A support member that rotatably supports the thermal head with respect to the frame,
The rotating shaft of the platen roller and the thermal head are interposed between the rotating shaft of the platen roller and the thermal head, and are in contact with at least one of the components of the platen roller and the thermal head. A mechanism for adjusting the gap between the thermal head and the platen roller by adjusting the distance between the thermal head and the platen roller is provided.
The adjustment mechanism
It has a cam lever provided on the outside of the side wall portion of the frame as the bearing.
The rotation shaft of the platen roller and the thermal head are brought into contact with each other by rotating the cam lever while the outer peripheral surface of the cam portion of the cam lever is in contact with the protrusion provided so as to project downward from the side wall portion of the support member. Adjust the distance between
A thermal printer comprising a fixing means for fixing the cam lever to the side wall portion of the frame by penetrating the cam lever from the outside of the cam lever. The thermal printer according to claim 1 , wherein the fixing means is screwed.

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